This invention is generally directed to a novel drive system which provides increased resistance to torsional stresses imposed on the drive system of a headed stud. More particularly, the invention contemplates a novel drive system which provides for increased strength to resist torsional shearing between a drive head and a stud body by providing a novel transitional portion between the drive head and the body.
Prior art studs have been formed with drive heads on a drive end thereof. For example, using a TORX.RTM. drive head, the male portion of the drive head is formed on a free end of the stud. The crest of the TORX.RTM. drive head has previously, necessarily, been formed with a diameter which is less than the diameter of the thread root formed on the body of the stud in order to prevent forming a thread on the lobes of the TORX.RTM. drive head. The TORX.RTM. drive head can shear off the stud as a result of the torsional stresses imposed on the drive head being greater than the strength of the material between the drive head and the body of the stud.
The present invention provides a novel drive structure which improves the prior structure to provide further resistance to torsional shearing of the drive head from the stud body by providing a transitional portion between the drive head and the body of the stud. Other features and advantages of the present invention will become apparent upon a reading of the attached specification in combination with a study of the drawings.